Protective device for internal combustion engines



May 27, 1958 D. C.IKINNEY 2,336,164

PROTECTIVE DEVICE FOR INTERNAL COMBUSTION mamas Filed March 3, 1955 2 Sheets-Sheet 1 INVENTOR.

DAVID c. KINNEY ATTORNEYS May 27, 1958 D. c. KINNEY 2,836,164

PROTECTIVE DEVICE FOR INTERNAL COMBUSTION ENGINES Filed March 3, 1955 2 Sheets-Sheet 2 FIG.3.

INVENTOR.

DAVID C. KINNEY BY m 4444?,

ATTORN S United States Patent PROTECTIVE DEVICE FOR INTERNAL COMBUSTION ENGINES David C. Kinney, East Detroit, Mich., assignor to Continental Motors Corporation, Detroit and Muskegon, Mich., a corporation of Virginia Application March 3, 1955, Serial No. 491,881

4 Claims. (Cl. 123-196) The present invention relates to a protective device for internal combustion engines and more specifically to a device for preventing the operation of an engine when there is insuflicient lubricating oil present.

In the usual small internal combustion engine in which a quantity of lubricating oil is carried in the crankcase and distributed to the pistons and cylinders by splashing the high and low oil levels are not usually indicated. The addition of too much oil usually causes an overflow but there is not usually any indication of a low level.

Among the objects of the present invention is to provide means for preventing the operation of the engine when the oil level has reached or is below a safe low level.

Another object is to provide means for interrupting the ignition circuit when the low oil level is reached.

Still other objects and advantages will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings in which- Fig. 1 is a partial view in elevation with parts in section of a stationary internal combustion engine involving the present invention.

Fig. 2 is a sectional view of the lower part of the crankcase in line 22 of Fig. 1.

Fig. 3 is a top plan view of the parts shown in Fig. 2.

Fig. 4 is a section on line 4-4 of Fig. 3.

In the drawings, there is indicated diagrammatically an engine having a cylinder housing 10, a flywheel housing 11, crankcase 12 and with part of the flywheel housing broken away to show the stator 15 of a flywheel magneto.

From the magneto 15 an insulated conductor 16 is shown as extending to the lower portion of the crankcase where it is secured to the outer end of a metal rod or probe 17 extending through but insulated from a wall 12A of the crankcase 12.

Within the crankcase is a small pan 20 having a curved bottom, and located so that the crank end of the piston rod (not shown) dips into the oil therein as the crank rotates. The pan 20 is supplied with oil from the main body of oil in the crankcase 12 through a small opening 20A. The pan 20 is supported upon two pillars 21 spaced a short distance apart and extending up from the bottom of the crankcase. As shown, one of the upper side edges of the pan 20 is bent outwardly to provide a flange 20B to provide a means by which the pan is attached to the pillars 21.

Fixed to the flange 20B is a pair of guide strips 22 and 23, the latter 23, extending downwardly a short distance and the former 22 extending downwardly to near the bottom of the crankcase 12 and being bent at right angles to provide a portion 22A extending toward the pan 20 and between pillars 21.

In the space between strips 22-23 and the adjacent vertically extending wall of pan 20 is a small float 25 of 1836, 1 64 Patented May 27, 1958 such dimensions that, as the oil level moves up and down, it will be guided in its movement by the pillars 21, the wall of pan 20 and the strips 22-23.

The probe 17 is of such length within the crankcase as to extend to a point within the float space and substantially at the level of the guide strip portion 22A, which level is such that when the level of the oil supporting the float 25 drops to a low unsafe level, the float will contact the probe 17 and the strip portion 22A. When this contact is made, it establishes a ground connection and the low voltage primary of the magneto is shorted, immediately stopping the engine and preventing further operation until oil has been added.

I claim:

1. In an internal combustion engine having magneto ignition, a crankcase containing a supply of oil, a dip pan supported in said crankcase, means communicating the interior of said dip pan with the oil in said crankcase, an electrically conductive float in said crankcase and exterior of said dip pan, said dip pan constructed and arranged to substantially overlie said float to shield same from oil splash disturbances, means guiding said float in vertical movement caused by a change of oil level in said crankcase, a pair of electrical conductor elements submerged in said oil exteriorly of said dip pan and arranged to be simultaneously contacted by said float at a predetermined oil level, one of said conductor elements being grounded and the other of said conductor elements being connected with the primary winding of the magneto and operable to electrically ground same when the oil level drops to the predetermined level aforesaid.

2. In an internal combustion engine having magneto ignition, a crankcase containing a supply of oil, a dip pan supported in said crankcase, means communicating the interior of said dip pan with the oil in said crankcase, an electrically conductive float in said crankcase and exterior of said clip pan, said dip pan constructed and arranged to substantially overlie said float to shield same from oil splash disturbances, means guiding said float in vertical movement caused by a change of oil level in said crankcase, a pair of electrical conductor elements submerged in said oil exteriorly of said dip pan and arranged to be simultaneously contacted by said float at a predetermined oil level, one of said conductor elements being grounded and the other of said conductor elements being connected with the primary winding of the magneto and operable to electrically ground same when the oil level drops to the predetermined level aforesaid, said other contact supported by and insulated from said crankcase and extending into said oil underneath said float.

3.1n an internal combustion engine having magneto ignition, a crankcase containing a supply of oil, a dip pan supported in said crankcase, means communicating the interior of said dip pan with the oil in said crankcase, an electrically conductive float in said crankcase and exterior of said dip pan, said dip pan constructed and arranged to substantially overlie said float to shield same from oil splash disturbances, means guiding said float in vertical movement caused by a change of oil level in said crankcase, a pair of electrical conductor elements submerged in said oil exteriorly of said dip pan and arranged to be simultaneously contacted by said float at a predetermined oil level, one of said conductor elements being grounded and the other of said conductor elements being connected with the primary winding of the magneto and operable to electrically ground same when the oil level drops to the predetermined level aforesaid, said other contact supported by and insulated from said crankcase and extending into said oil underneath said float, said means communicating the interior of said dip pan with the oil disposed at a lower level in said crankcase than the level at which the float contacts the aforesaid elecrical conductor elements.

4. In an internal combustion engine having magneto ignition, a crankcase containing a supply of oil, a dip pan supported in said crankcase, means communicating the interior of said dip pan with the oil in said crankcase, an electrically conductive float in said crankcase and exterior of said dip pan, said dip pan constructed and arranged to substantially overlie said float to shield same from oil splash disturbances, means guiding said float in vertical movement caused by a change of oil level in said crankcase, a pair of electrical conductor elements submerged in said oil exteriorly of said dip pan and arranged to be simultaneously contacted by said float at a predetermined oil level, one of said conductor elements being grounded and the other of said conductor elements being connected With the primary winding of the magneto and operable to electrically ground same when the oil level drops to the predetermined level aforesaid, said float 4 a guiding means comprising substantially vertically disposed oil pan supporting posts arranged at opposite ends of said float, a substantially vertically inclined exterior wall cf said dip pan on one side of said float, and substantially vertically disposed members supported from the upper edge of said dip pan and spaced from the aforesaid wall of said clip pan to lie on the other side of said float.

References Cited in the file of this patent UNITED STATES PATENTS 946,923 Teeter Jan. 18, 1910 1,184,029 Schatz May 23, 1916 1,243,470 White Oct. 16, 1917 1,369,321 Buren Feb. 22, 1921 2,253,260 Alcorn Aug. 19, 1941 FOREIGN PATENTS 698,978 France Dec. 8, 1930 

